Page 1 of 1

### Question regarding: "E° + Value means reduction is spontaneous"

Posted: Mon Jan 30, 2017 7:46 pm
Hello, just a quick question on what "E° + Value means reduction is spontaneous" means. It's on page 46 of the course reader.

What do they mean by "value" and is there a case when E° is not spontaneous?

### Re: Question regarding: "E° + Value means reduction is spontaneous"

Posted: Mon Jan 30, 2017 7:50 pm
I think its "E positive value," not E plus value.

### Re: Question regarding: "E° + Value means reduction is spontaneous"

Posted: Sun Feb 05, 2017 6:08 pm
E° must always be positive or else the reaction will not occur. The value comes from the equation E°cell=E°cathode - E°anode. If E° were negative, the reaction would be non-spontaneous because the work would not be done by the system. On page 49, there is the equation deltaG°=-nFE°. If E°were negative then you would be multiplying a negative by a negative, making deltaG° positive, which means the reaction is non-spontaneous. Therefore, E° must always be positive.

### Re: Question regarding: "E° + Value means reduction is spontaneous"

Posted: Sun Feb 05, 2017 6:26 pm
Yeah if E°is negative then it would require outside energy in order for the reaction to occur.